This invention relates generally to accessories for water craft and more particularly concerns devices for signalling the absence of a drain plug from a boat drain when the boat is in a launch condition.
Prior art devices directed at saving the boating enthusiast from the embarrassment, aggravation and work resulting from launching a boat with an open drain fall into two basic categories. One category includes those devices responsive solely to the physical presence of a plug in the drain. In this category the alarm indicia are activated by the presence or absence of the plug in the drain and the alarm is activated regardless of the launch condition of the craft. For visual indicators which do not constantly bombard the senses, this can be an acceptable arrangement, but such indicators are inadequate in actual launch conditions because they require the boatman to physically observe the indicia. The boatman is still reliant on memory to check for the presence of the plug by looking at the indicia. For audio indicators of this type, the plug must always be in the drain, even if the boat is not in a launch condition, to prevent a constant sounding alarm. Of course, a manual interrupt could be used to disconnect the circuit, but such an interrupt would, be self-defeating since it would disconnect the system and again place the burden of memory on the boatman. The other category includes those devices responsive to the presence of water to activate the alarm. Some water responsive devices are presently known, but are actuated by either the presence of water in or the flow of water into the boat. Consequently, while such devices are satisfactory to minimize the embarrassment, aggravation and work above referred to, they do not eliminate it.
An additional problem with known indicator devices is that they require insertion and removal of the drain plug from a position inside of the boat. This can be a very inconvenient operation, particularly when the drain plug is located beneath floor boards or is inaccessible due to the presence of other boat equipment such as engines, pumps and the like.
It is therefore an object of the present invention to provide a drain plug absence indicator which gives an audible warning only if the boat is in a launch condition and the drain plug is absent from the drain. Another object of the present invention is to provide a drain plug absence indicator capable of giving an alarm prior to the flow of water through the drain. And it is an object of the present invention to provide a drain plug indicator which allows insertion and removal of the drain plug from a position outside of the boat.